Op art works are abstract, with many better known pieces created in black and white. Typically, they give the viewer the impression of movement, hidden images, flashing and vibrating patterns, or of swelling or warping.

Time Magazine coined the term op art in 1964, in response to Julian Stanczak's show Optical Paintings at the Martha Jackson Gallery, to mean a form of abstract art (specifically non-objective art) that uses optical illusions.[3][4] Works now described as "op art" had been produced for several years before Time's 1964 article. For instance, Victor Vasarely's painting Zebras (1938) is made up entirely of curvilinear black and white stripes not contained by contour lines. Consequently, the stripes appear to both meld into and burst forth from the surrounding background. Also, the early black and white "dazzle" panels that John McHale installed at the This Is Tomorrow exhibit in 1956 and his Pandora series at the Institute of Contemporary Arts in 1962 demonstrate proto-op art tendencies. Martin Gardner featured op Art and its relation to mathematics in his July 1965 Mathematical Games column in Scientific American. In Italy, Franco Grignani, who originally trained as an architect, became a leading force of graphic design where op art or kinetic art was central. His Woolmark logo (launched in Britain in 1964) is probably the most famous of all his designs.[]

"Op artists thus managed to exploit various phenomena," writes Popper, "the after-image and consecutive movement; line interference; the effect of dazzle; ambiguous figures and reversible perspective; successive colour contrasts and chromatic vibration; and in three-dimensional works different viewpoints and the superimposition of elements in space."[2]

Some members of the group Nouvelle tendance (1961-1965) in Europe also were engaged in op art as Almir Mavignier and Gerhard von Graevenitz, mainly with their serigraphics. They studied optical illusions. The term op irritated many of the artists labeled under it, specifically including Albers and Stanczak. They had discussed upon the birth of the term a better label, namely perceptual art.[5] From 1964, Arnold Schmidt (Arnold Alfred Schmidt) had several solo exhibitions of his large, black and white shaped optical paintings exhibited at the Terrain Gallery in New York.[6]

The exhibition was enormously popular with the general public (the attendance was over 180,000),[9] though less so with the critics.[10] Critics dismissed op art as portraying nothing more than trompe-l'oeil, or tricks that fool the eye. Regardless, op art's popularity with the public increased, and op art images were used in a number of commercial contexts. One of Brian de Palma's early works was a documentary film on the exhibition.[11]

Method of operation

Black-and-white and the figure-ground relationship

Op art is a perceptual experience related to how vision functions. It is a dynamic visual art that stems from a discordant figure-ground relationship that puts the two planes--foreground and background--in a tense and contradictory juxtaposition. Artists create op art in two primary ways. The first, best known method, is to create effects through pattern and line. Often these paintings are black-and-white, or otherwise grisaille--as in Bridget Riley's famous painting, Current (1964), on the cover of The Responsive Eye catalogue. Here, black and white wavy lines are close to one another on the canvas surface, creating a volatile figure-ground relationship. Getulio Alviani used aluminum surfaces, which he treated to create light patterns that change as the watcher moves (vibrating texture surfaces). Another reaction that occurs is that the lines create after-images of certain colors due to how the retina receives and processes light. As Goethe demonstrates in his treatise Theory of Colours, at the edge where light and dark meet, color arises because lightness and darkness are the two central properties in the creation of color.[]

Color

Beginning in 1965 Bridget Riley began to produce color-based op art;[12] however, other artists, such as Julian Stanczak and Richard Anuszkiewicz, were always interested in making color the primary focus of their work.[13]Josef Albers taught these two primary practitioners of the "Color Function" school at Yale in the 1950s. Often, colorist work is dominated by the same concerns of figure-ground movement, but they have the added element of contrasting colors that produce different effects on the eye. For instance, in Anuszkiewicz's "temple" paintings, the juxtaposition of two highly contrasting colors provokes a sense of depth in illusionistic three-dimensional space so that it appears as if the architectural shape is invading the viewer's space.

Color interaction

Intrinsic Harmony, by Richard Anuszkiewicz, 1965

There are three major classes of the interaction of color: simultaneous contrast, successive contrast, and reverse contrast (or assimilation). (i) Simultaneous contrast may take place when one area of color is surrounded by another area of a different color. In general, contrast enhances the difference in brightness and/or color between the interacting areas. Such contrast effects are mutual, but if the surround area is larger and more intense than the area it encloses, then the contrast is correspondingly out of balance, and may appear to be exerted in one direction only. (ii) In successive contrast, first one color is viewed and then another. This may be achieved either by fixing the eye steadily on one color and then quickly replacing that color with another, or by shifting fixation from one color to another. (iii) In reverse contrast (sometimes called the assimilation of color or the spreading effect) the lightness of white or the darkness of black may seem to spread into neighbouring regions. Similarly, colors may appear to spread into or become assimilated into neighbouring areas. All effects tend to make neighbouring areas appear more alike, rather than to enhance their differences as in the more familiar simultaneous contrast, hence the term reverse contrast (Jameson and Hurvich). Note that in the interaction of color the constituent colors retain much of the own identity even though they may be altered somewhat by contrast.

-- Floyd Ratliff, The Theory of Color and the Practice of Painting[14]

Bridget Riley has had several international exhibitions in recent years (e.g. Dia Center, New York, 2000; Tate Britain, London, 2003; Museum of Contemporary Art, Sydney, 2004).

Photographic op art

Although being relatively mainstream, photographers have been slow to produce op art. In painting, Victor Vasarely and Bridget Riley were producing large amounts of art and the same can be said for many digital artists, such as Akiyoshi Kitaoka. One of the primary reasons for the lack of photographers doing op art, is the difficulty in finding effective subject matter. László Moholy-Nagy produced photographic op art and taught the subject in the Bauhaus. One of his lessons consisted of making his students produce holes in cards and then photographing them.